Do not return the tag as branch name for GitLab CI

[AlphaYankee]

In case of a tag pipeline, return null as branch name instead of the tag

Description

For tag pipelines (triggered by tagging a commit), do not return CI_COMMIT_REF_NAME as the current branch because in this case it contains the new tag instead of a branch.

Related Issue

Fixes #4186

Motivation and Context

Bugfix

How Has This Been Tested?

Manually tested the following scenarios on GitLab CI:

• Commit
• Tag
• Branches
• Merge requests

Also ran the tests in the solution.

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[HHobeck]

Hi there.

What happens:

• when you trigger a tag (pre-release version) from lets say development branch?
• when the tag is on main and merged to development?

Would be good to have some integration tests to cover your scenario.

[AlphaYankee]

I think this should cover the Scenarios (label for main branches is "dev")...

Unfortunately at the moment I don't think I'll have the time to find out how to create those automated tests and implement them.

Tag branch master with v1.2.0

"FullSemVer": "1.2.0"
"InformationalVersion": "1.2.0+Branch.master.Sha.f638f0ff709f763982676abd6698a678889302a1"
(in 6.0.2 this would result in FullSemVer=1.2.1-v1-2-0.1+0)

Create branch development from master

"FullSemVer": "1.2.1-development.1+0"
"InformationalVersion": "1.2.1-development.1+0.Branch.development.Sha.f638f0ff709f763982676abd6698a678889302a1"
(same as in 6.0.2)

Commit on development

"FullSemVer": "1.2.1-development.1+1"
"InformationalVersion": "1.2.1-development.1+1.Branch.development.Sha.c04e043529d8e0809d55e3b1d8b5ea70f4fb7b9a"
(same as in 6.0.2)

Tag branch development with v1.3.0

"FullSemVer": "1.3.1-development.1+0"
"InformationalVersion": "1.3.1-development.1+0.Branch.development.Sha.c04e043529d8e0809d55e3b1d8b5ea70f4fb7b9a"
(in 6.0.2 this would result in FullSemVer=1.3.1-v1-3-0.1+0)

Merge branch development into master

FullSemVer": "1.3.1-dev.1"
"InformationalVersion": "1.3.1-dev.1+Branch.master.Sha.ddfcf3381ca1dba1b4ad77f407d4ee1d560e8fc1"
(same as in 6.0.2)

Commit on master

"FullSemVer": "1.3.1-dev.2"
"InformationalVersion": "1.3.1-dev.2+Branch.master.Sha.c2e373ff0ff90010a835d158b53a9f9d524d4355"
(same as in 6.0.2)

Tag branch master with v1.3.1

"FullSemVer": "1.3.1"
"InformationalVersion": "1.3.1+Branch.master.Sha.c2e373ff0ff90010a835d158b53a9f9d524d4355"
(in 6.0.2 this would result in FullSemVer=1.3.2-v1-3-1.1+0)

Merge branch master into development

"FullSemVer": "1.3.2-development.1+1"
"InformationalVersion": "1.3.2-development.1+1.Branch.development.Sha.69092abd47e89cc20688853b0f0fa5523d6e58fa"
(same as in 6.0.2)